Current supply apparatus



Aug. 11, 1931. w, c, GRUNOW 1,818,947

CURRENT SUPPLY APPARATUS FiledOct. 6, 1926 Patented Aug. 11, 1931 UNITED STATES PATENT OFFICE 1 WILLIAM G. GRUNOVI', OF CHICAGO, ILLINOIS, ASSIGNOR TO GRIGSBY- GRUNOW COM- PANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS CURRENT SUPPLY APPARATUS,

-. Application filed October 6, 1926. Serial No. 139,788

My invention relates to B current supply apparatus and has to do more particularly with the provision of an improved circuit arrangementhaving certain new features of control whereby the current supply apparatus 'is adapted for a greater range of use and for use with a greater range of the number of tubes employed in the receiving set.

i. The present application is directed more m particularly to the circuit arrangement and for improved apparatus adapted for use with this circuit reference may be made to my copending application for B current supply,

M Serial Number 139,790, filed of even date herewith. e

For a better understanding of my invention reference is to be had to the accompanying drawing, in which a diagrammatic circuit arrangement is illustrated adapted for wiring up apparatus whereby the B current for a radio receiving apparatus may be supplied from the ordinary alternating current as supplied for general household and commercial use, and which is more generally 110 volts. However, my invention is not limited to any particular voltage, nor the usual 60 cycle current.

Referring now more in detail to the apparatus employed, I show a transformer T having a primary winding 1 and split secondary winding 2. The primary winding is adapted to be connected to the incoming line conductors at the terminals 3 1 and a two way switch S is shown connected in circuit for varying the connections to the primary winding and thereby varying the input current. One side of the incoming line is adapted to be connected to a binding post for connection to ground, as I find that thiselimio nates some of the disturbance otherwise present.

The spilt winding of the secondary 2 has its opposite ends connected to the anodes 56 of a suitable rectifying tube, and in the particular circuit illustrated I preferably employ a Raytheon rectifying tube of known con- 5 6 conductor of the apparatus which also is connected to the core of the transformer and through condensers 89 as illustrated.

The cathode 10 of the rectifying tube is extended as the plus or positive side 11 of the feed circuit with a pair of high inductance choke coils I and I in series. Suitable condensers 12131 1 are bridged across the line conductors and around the choke coils and I also connect the cores of these two coils by conductors 1516 with the negative conductor 7, as I find this eliminates disturbance otherwise present.

The two feed conductors 711 terminate in suitable binding posts or terminals 44- 11, and a terminal 43 extending through a variable resistance R to the positive conductor 11 is also provided for supplying current to the detector tap or terminal of the receiving set. A fixed high resistance R and condenser 17 are bridged across the terminals i3l4:.

One of the features of my improved circuit arrangement is the provision of the connec tion from terminal 42 through the variable high resistance R whereby a tapisprovided for the radio frequency amplification connection or intermediate plate voltage connection where present on'the set being used. This resistance R is also bridged by a condenser 18 and the elements R18 have a central tap extending through the condenser 19 to the negative side of the line.

It is to be understood that I do not claim the general circuit of the rectifying and filtering arrangements illustrated, but only those particular improvements specified and claimed.

The circuit arrangement as here illustrated and when used with the apparatus illustrated and described in my said copending application is adapted for use with the various well known receiving sets now on the market.

In order to apply the circuit arrangement illustrated and connect it with the receiving set, the negative binding post 44 is connected to the corresponding terminal on the receiv ing set which is ordinarily marked Neg. or "13. Now connect the detector binding post 48 to the corresponding terminal on the receiving set which will be marked Det. or plus 22 or plus 45. i l

If the receiver has only three binding posts on the B side, then connect the intermediate binding post 42 to the 90 volt terminal on the receiving set generally marked plus 90 or Amp. or Amp. B plus.

If the receiving set has four terminals on the B side, including one for radio frequency amplification or intermediate plate voltage, then connect the terminal on the receiving set marked plus 67 or plus 90 to the intermediate post 42. Also connect the binding post on the set marked Amp. or B plus or plus 135 to the binding post a1 of the circuit illustrated.

For controlling the circuit here illustrated when used with the receiving set the variable resistance R controls the detector voltage and the variable resistance It adjusts the voltage to the intermediate tap through binding post 42.

In the ordinary use of the circuit a ground connection is not required to the binding post 45 so as to ground one of the incoming line conductors, but if line noises are heard, which sometimes occurs due to bad grounding of the line circuit, this can usually be eliminated by grounding this terminal 45.

It will thus be seen that with the improved circuit arrangement the intermediate plate voltage tap with control therefor is provided.

What I claim as new and desire to secure by United States Letters Patent is 1. In a current supply circuit, a rectifying and filter circuit including a transformer, condensers in parallel with said circuit, choke impedance coils in series with said circuit, a rectifying tube for supplying rectified current to said circuit, positive and negative outgoing connecting terminals for the circuit, a detector terminal, connections therefor, a variable resistor for varying the voltage value at the detector terminal, a fourth terminal for radio frequency amplification or intermediate plate voltage supply and connections therefor, and a variable resistor included in the last said connections for varying the voltage thereof, the last said connections including said last resistor and a condenser in series across leads going to the said positive and negative terminals and a condenser in shunt of the resistor.

2. In a current supply circuit, a rectifying and filter circuit including a transformer, condensers in parallel with said circuit, choke impedance coils in series with said circuit, a rectifying tube for supplying rectified current to said circuit, positive and negative outgoing connecting terminals for the circuit, a detector terminal, connections therefor, a variable resistor for varying the voltage value at the detector terminal, a fourth terminal for radio frequency amplification or intermediate plate voltage supply and connections therefor, and a variable resistor included in the last said connections for varying the voltage thereof, the last said connections including said last resistor and a condenser in series across leads going to the said positive and negative terminals and a condenser in shunt of the resistor with said fourth terminal connected at a point between the serially connected condenser and resistor.

3. In a current supply circuit, a rectifying and filter circuit including a transformer, condensers in parallel with said circuit, choke impedance coils in series with said circuit, a rectifying tube for supplying rectified current to said circuit, positive and negative outgoing connecting terminals for the circuit, a detector terminal, connections there for, a variable resistor for varying the voltage at the detector terminal and connected to the positive side of the rectified circuit, a relatively high resistance and a condenser connected in parallel between a detector connector and the negative side of said rectifying circuit and a fourth terminal having voltage regulating means independent of the voltage control means for said detector terminal.

4.111 a current supply circuit, a rectifying and filter circuit including a transformer, condensers in parallel with said circuit, choke impedance coils in series with said circuit, a rectifying tube for supplying rectified current to said circuit, positive and negative outgoing terminals for the circuit, a terminal for intermediate plate voltage supply and connections therefor, and a resistor included in the intermediate terminal connection for reducing the voltage thereof, a condenser connected across from the intermediate terminal connection to the positive side of the rectifying circuit, and a condenser connected across from the intermediate connection to the negative side of the rectifying circuit.

5. In a current supply circuit, a rectifying and filter circuit including a transformer, condensers in parallel with said circuit, impedance coils in series with said circuit, a rectifying tube for supplying rectified current to said circuit, positive and negative outgoing terminals for the circuit, a terminal for intermediate voltage supply, a variable resistance connecting said terminal to one outgoing terminal, a condenser shunting said resistance, a condenser connecting said termi nal to the other positive terminal, and a detector terminal having voltage regulating means independent of the voltage control means for said intermediate terminal.

In witness whereof, I hereunto subscribe my name this 11th day of September. 1926.

IVILLIAM C. GRUNOW. 

